JP5193627B2 - Image forming apparatus - Google Patents

Description

The present invention is used in a copying machine, a printer, a facsimile machine, or a multi-function machine functionally equipped with these, and is provided with an image forming apparatus provided with a cleaning device for cleaning the surface of an image carrier after the image is transferred onto the transfer paper surface. Relates to the device.
The present invention relates to an image forming apparatus.

  Conventionally, in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine functionally equipped with these, an electrostatic latent image formed on a photoreceptor is visualized as a toner image by a developer (toner). Subsequently, it is well known that the toner image is first transferred onto an intermediate transfer belt and then secondarily transferred onto the surface of the transfer paper.

  In addition, such an image forming apparatus includes a cleaning device that cleans residual toner remaining without being transferred onto the surface of the intermediate transfer belt after the secondary transfer for the next image forming process. The arrangement is also well known.

  This cleaning device includes a cleaning brush such as a fur brush that contacts the surface of the intermediate transfer belt, a recovery roller that applies a cleaning bias to the cleaning brush, and a cleaning blade that contacts the surface of the recovery roller in the counter direction (for example, made of rubber ).

As a result, the toner can be recovered via the recovery roller after being electrostatically removed by the residual toner cleaning brush remaining on the surface of the intermediate transfer belt (see, for example, Patent Document 1).
JP 2004-184863 A

  However, in the brush cleaning method for cleaning the surface of the intermediate transfer belt using the cleaning brush employed in the above-described image forming apparatus, for example, relatively little torque fluctuation is applied to the intermediate transfer belt as the image carrier. The cleaning mechanism that presses and separates the cleaning brush is particularly excellent in terms of following the speed fluctuation of the intermediate transfer belt, but when a conductive material such as a metal roller is used as the recovery roller. There is an influence depending on the print pattern at the contact portion between the cleaning brush and the collection roller.

  For example, in a system in which a bias is applied to the shaft of the conductive recovery roller and a current path is formed from the cleaning brush, the intermediate transfer belt, and the counter electrode roller, the printed portion and the remaining portion where residual toner always exists Since the degree of contamination of the cleaning brush by the toner external additive contained in the toner differs from the non-printing portion where no toner is present, the longitudinal direction between the cleaning brush and the collection roller (the width orthogonal to the transfer paper conveyance direction) The direction of the cleaning current in the direction is greatly different.

  As a result, overcurrent occurs more than necessary in the non-printing area, and this overcurrent not only prevents the desired recovery potential difference between the surface of the recovery roller and the cleaning brush, but also adheres to the cleaning brush. A phenomenon occurs in which the toner is reversed in polarity due to the charge injection into the remaining toner.

  Further, when this toner is reversed in polarity, the residual toner cannot be collected from the cleaning brush to the collecting roller by electrostatic force, and a large amount of residual toner accumulates on the cleaning brush, so that the cleaning performance of the cleaning brush is remarkable. There have been problems such as reduction and residual toner reattachment to the intermediate transfer belt.

  Therefore, in order to prevent the occurrence of overcurrent, it is conceivable to set the bias applied to the collecting roller low. In this case, however, the cleaning current in the printing portion is insufficient, and as a result, the intermediate transfer belt There arises a new problem that the toner recovery performance to the cleaning brush, that is, the cleaning performance is deteriorated.

  In this case, since the amount of toner collected on the collecting roller is reduced, the adhesion between the cleaning blade and the collecting roller is increased, and the driving torque of the collecting roller is increased depending on the pressing force of the cleaning blade, and mechanical jitter is reduced. There is a problem that it is likely to occur.

  Further, there may be a toner external additive such as silica having a smaller particle diameter and higher hardness than the remaining toner near the nip portion between the cleaning blade and the collecting roller. When entering, the friction is generated by being strongly pressed against the surface of the collecting roller, and the surface of the collecting roller is worn, resulting in a problem that the surface resistance of the collecting roller is reduced entirely or partially.

  Therefore, in consideration of the above circumstances, the present invention can make the surface of the collecting roller low in friction and high in hardness, and can secure a necessary cleaning current, thereby improving the cleaning performance. An object is to provide a forming apparatus.

  The image forming apparatus of the present invention is an image forming apparatus provided with a cleaning device that removes residual toner after transfer remaining on the surface of an image carrier that transfers a toner image onto a transfer paper, and is in contact with the surface of the image carrier. A cleaning brush made of conductive fibers for removing the residual toner from the surface of the image carrier, a recovery roller for electrostatically collecting the residual toner removed by the cleaning brush from the cleaning brush, and a fluororesin. A resistance layer formed on the surface of the collecting roller so as to have a surface resistivity of 1.0E + 8 to 1.0E + 12Ω / □ as a component, and a toner scraping member that scrapes off residual toner collected by the collecting roller. It is characterized by.

  At this time, the friction coefficient of the resistance layer is preferably set to 0.2 or less. The resistance layer preferably has a thickness of 20 ± 4 μm.

  Moreover, it is preferable that a filler is added to the material component of the resistance layer, and potassium titanate whisker or acicular titanium oxide is preferably used as the filler.

  Furthermore, it is preferable that a conductive filler made of a tin oxide conductive agent is dispersedly coated on the surface of the resistance layer.

  The image forming apparatus of the present invention can make the surface of the collecting roller low in friction and high in hardness, and can secure a necessary cleaning current, thereby improving the cleaning performance.

  Next, a cleaning device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory view of an example of an image forming apparatus provided with a cleaning device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part of the cleaning device in the image forming apparatus according to an embodiment of the present invention. .

[Entire configuration of image forming apparatus]
As shown in FIG. 1, a printer 1 as an image forming apparatus according to an embodiment of the present invention is connected to a computer or the like (not shown), and generates a full-color image based on image information sent from the computer or the like. Transfer and fix on transfer paper. The right side of the printer 1 is the front side operated by the operator.

  The printer 1 includes a photoreceptor 2 on which an electrostatic latent image is formed, a rotary developing device main body 3 as a developing unit, a laser unit 4 as an exposure device, and a toner container 5 containing replenishing toner. The toner supply member 6 supplies the replenishing toner contained in the toner container 5 to the rotary developing device main body 3, the intermediate transfer unit 7, the secondary transfer roller 8, and the fixing device 9.

[Configuration of Photoreceptor 2]
The photosensitive member 2 is rotatably provided in the center of the inside of the printer 1 and its rotation shaft is provided so as to extend in the width direction from the front side of the printer 1, that is, to extend in the depth direction in FIG. Yes. A charging roller 10 for uniformly charging the surface of the photoconductor 2 is provided on the photoconductor 2. Further, a drum cleaning device 11 for cleaning toner and adhering matter remaining on the surface of the photoconductor 2 is provided on the side of the photoconductor 2.

[Configuration of Rotating Developing Device Body 3]
The rotary developing device main body 3 develops the electrostatic latent image formed on the photoconductor 2 with toner of each color, and is adjacent to the photoconductor 2 and its rotation center is substantially the same as the rotation center of the photoconductor 2. It is provided to be at the height position. The rotary developing device main body 3 has a cylindrical shape that is rotatable about an axis parallel to the rotation center axis of the photoreceptor 2 and is rotated by a drive system including a motor and gears (not shown). Further, the rotary developing device main body 3 is divided into four equal parts in this embodiment, and corresponds to four toners (for example, yellow (Y), magenta (M), cyan (C), and black (K)). The developing device 12 can be installed.

  Each developing device 12 has substantially the same configuration, and is provided with a developing roller 13 and the like that can be disposed facing the photosensitive member 2. In addition, each developing device 12 is disposed away from the toner container 5, thereby reducing the toner storage space of the rotary developing device main body 3 and reducing the size of the developing device 12. Further, the developing device 12 can be attached to and detached from the rotary developing device main body 3 respectively, and maintenance and replacement of the developing device 12 can be easily performed.

  Each of the developing devices 12 has a tip of the toner replenishing member 6 on the outer peripheral surface of the toner case 14 constituting the outer shape of the developing device 12 in order to replenish the replenishing toner from the toner container 5 into the developing device 12. A toner replenishing portion (not shown) made of an elastic material such as rubber having a slit or the like (not shown) is provided.

[Configuration of Laser Unit 4]
The laser unit 4 scans and exposes the photoconductor 2 based on image information sent from an external computer or the like, and is disposed above the photoconductor 2. The laser unit 4 is provided with known configurations such as a laser light source, a polygon mirror, and a polygon mirror driving motor (not shown). Further, a reflection mirror 15 is provided in front of the laser beam path of the laser unit 4, and the laser light emitted from the laser unit 4 is bent by the reflection mirror 15 and irradiated onto the surface of the photosensitive member 2. It is like that.

[Configuration of Toner Container 5]
The toner container 5 stores replenishment toner corresponding to each developing device 12 of the rotary developing device main body 3, and is detachably installed in the printer 1 so as to be replaceable. Further, the toner container 5 is yellow (Y), magenta (M), cyan (C), black (from the one side surface of the printer 1 toward the other side surface (toward the depth direction in FIG. 1)). The four toner containers 5 containing the replenishment toners of the respective colors K) are independently arranged in parallel.

[Configuration of Toner Supply Member 6]
The toner replenishing member 6 is for supplying the toner of each color stored in the toner container 5 to the corresponding developing device 12, and between the laser unit 4 and the toner container 5 above the photoreceptor 2. Arranged in space. Further, the same number of toner replenishing members 6 as the toner containers 5 are arranged so as to be movable in the vertical direction. The toner replenishing members 6 face the respective developing devices 12 at positions shifted in the depth direction of the paper surface of FIG. 12 can be replenished.

  The replenishing toner supplied to each developing device 12 contains at least one of titanium oxide, silicon oxide, zinc oxide, aluminum oxide, silica, and the like, which are inorganic oxide fine particles, as an external toner additive. .

[Configuration of Intermediate Transfer Unit 7]
The intermediate transfer unit 7 sequentially transfers the toner images of the respective colors formed on the photosensitive member 2 to an endless intermediate transfer belt 16 and is disposed below the photosensitive member 2 and the toner container 5. The intermediate transfer belt 16 is stretched between a driving roller 17 and driven rollers 18 and 19 which are disposed apart from each other. Further, the portion of the intermediate transfer belt 16 that faces the photoconductor 2 is configured to contact the photoconductor 2 by the primary transfer roller 20. In this embodiment, the driven roller 18 has a function of a tension roller for maintaining the tension state of the intermediate transfer belt 16. Further, the intermediate transfer belt 16 is cleaned by a cleaning device 21 disposed below the rotary developing device main body 3.

  The drive roller 17 is disposed substantially directly below the contact portion between the photosensitive member 2 and the rotary developing device main body 3, and the center thereof is located further below the lowermost end of the rotary developing device main body 3. And it drives by the drive part containing the motor and gear which are not shown in figure.

  The driven roller 18 is disposed close to the bottom of the toner container 5 on the front side of the printer 1, and the height position thereof is substantially the same as that of the photoreceptor 2.

  The primary transfer roller 20 is provided below the photoconductor 2, whereby a predetermined range of the intermediate transfer belt 16 is in contact with the photoconductor 2.

[Configuration of Secondary Transfer Roller 8]
The secondary transfer roller 8 is for secondary transfer of the image transferred to the intermediate transfer belt 16 to the transfer paper that has been conveyed, and is disposed below the driving roller 17 so as to face the transfer sheet. The secondary transfer roller 8 is applied with a bias voltage for image transfer to the transfer paper by a voltage application unit (not shown).

[Configuration of Fixing Device 9]
The fixing device 9 heats and presses the toner (image) transferred onto the transfer paper from the front and back of the transfer paper in order to melt and fix the toner, and is disposed below the rotary developing device main body 3 and near the back of the printer 1. ing. The fixing device 9 includes a fixing roller 23 that is heated by heat generated by a heat source 22 such as a halogen heater, and a pressure roller 24 that is in pressure contact with the fixing roller 23.

[Configuration of transport route]
A paper feed cassette 25 for storing transfer paper (not shown) is provided at the bottom of the printer 1. The transfer paper stored in the paper feed cassette 25 is taken out from the paper feed unit 26 and transported to a transport path 28 leading to the discharge port 27, and the image transfer / fixing process described above is performed in the transport process. The The paper feed cassette 25 can be pulled out from the front side of the printer 1 for replacement or replenishment of transfer paper.

  Further, a manual feed tray 29 that can be turned up and down is provided on the side surface of the printer 1, and transfer paper can be mounted on the manual feed tray 29. The transfer paper loaded on the manual feed tray 29 is taken out from the manual paper feed unit 30 and joined to the transport path 28, and the image transfer / fixing process described above is performed in the transport process.

  Further, on the upstream side of the secondary transfer roller 8 in the conveyance path 28, a resist for adjusting the timing between the leading edge of the transfer paper taken out from the paper feeding unit 26 or the manual paper feeding unit 30 and the intermediate transfer belt 16. A pair of rollers 31 is provided, and on the downstream side of the fixing device 9 in the conveyance path 28, the transfer paper that has been fixed for double-sided printing processing is reversely conveyed from the registration roller pair 31 to the upstream side of the conveyance path 28. An inversion path 32 is provided. At this time, after the transfer paper for reversing is once transported to the vicinity of the discharge port 27, the rear end of the transfer paper is transported downstream of the upstream port of the reversing path 32 in the transport path 28. When the switchback roller 33 is reversed, it is fed into the reverse path 32.

[Image forming operation]
In the above configuration, when the printer 1 is turned on, various parameters are initialized, and initial settings such as setting the temperature of the fixing device 9 are performed. When image data is input from a computer or the like connected to the printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  During the image forming operation, the toner replenishing member 6 is moved away from the rotary developing device main body 3 to the upper retracted position.

  First, after the photosensitive member 2 is charged by the charging roller 10, scanning exposure corresponding to the image data is performed on the photosensitive member 2 by the laser unit 4, and an electrostatic latent image is formed on the photosensitive member 2.

  Next, the rotary developing device main body 3 is rotated so that the corresponding color developing device 12 is opposed to the photosensitive member 2. In this state, the electrostatic latent image on the photoreceptor 2 is developed with the corresponding color toner.

  The developed image is transferred to the intermediate transfer belt 16, and the above operation is sequentially repeated for each color, whereby a full-color image is formed on the intermediate transfer belt 16. Residual toner remaining on the photoreceptor 2 is cleaned by the drum cleaning device 11 and discarded in a waste toner container (not shown).

  On the other hand, the transfer paper positioned at the uppermost position of the paper feeding cassette 25 taken out by the paper feeding unit 26 is subjected to the secondary transfer after being matched with the image forming position on the intermediate transfer belt 16 by the registration roller pair 31. It is conveyed to the roller 8.

  Since the secondary transfer roller 8 is in contact with the intermediate transfer belt 16, the full color image formed on the intermediate transfer belt 16 is transferred onto the transfer paper by the transfer bias applied to the secondary transfer roller 8 and then fixed. Guided by the apparatus 9, the image is fixed on the transfer paper by heating and pressing by the fixing apparatus 9.

  The fixed transfer sheet is discharged from the discharge port 27 as it is via the switchback roller 33 in the case of single-sided printing. In the case of duplex printing, the switchback roller 33 switches back to the reverse path 32 and returns to the upstream side of the conveyance path 28 with respect to the registration roller pair 31, and then forms an image on the back side of the transfer paper. And then discharged from the outlet 27.

  Residual toner remaining on the intermediate transfer belt 16 after the transfer is removed by a cleaning device 21 employing a bias cleaning method, and then discarded in a waste toner container (not shown).

[Cleaning device 21]
Hereinafter, specific examples of the cleaning device 21 of the present invention will be described.

  As shown in FIG. 2, the cleaning device 21 includes a cleaning brush 34 made of a cylindrical electrostatic fur brush or the like in which a large number of brush fibers (conductive) are wound around a metal core so as to be in contact with the surface of the intermediate transfer belt 16. And a recovery roller 35 that collects a predetermined amount of toner in the cleaning brush 34 and collects the residual toner scraped off by the cleaning brush 34, and scrapes the residual toner recovered by the recovery roller 35 in contact with the surface of the recovery roller 35. A cleaning blade 36 as a toner scraping member, and a spiral 37 that transports residual toner and the like scraped by the cleaning blade 36 to a waste toner container are provided.

  The cleaning brush 34 is, for example, a long woven fabric in which resinous brush fibers (filaments) such as nylon 6 are densely planted and bonded in a spiral shape to form a roll. Fluorine-based resin powder (for example, Mitsubishi Oil Kainer 500 etc.) may be applied in advance as a lubricant.

  Further, the cleaning brush 34 is in contact with the surface of the intermediate transfer belt 16 with a predetermined biting amount (A). The definition of the biting amount (A) is defined as the maximum value at which the tip of the brush fiber of the cleaning brush 34 enters the intermediate transfer belt 16 when the intermediate transfer belt 16 does not exist.

  In the present invention, the biting amount (A) is set to 1 ± 0.2 mm, but there is no particular problem as long as it is up to half the length of the brush fiber. The amount of biting (A) of the cleaning brush 34 is preferably set in the range of 0.5 to 1.5 mm.

  At the contact point between the intermediate transfer belt 16 and the cleaning brush 34, the linear velocity ratio between the intermediate transfer belt 16 and the cleaning brush 34 is preferably in the range of 0.5 to 2.0 (counter direction).

  This is because if the linear velocity difference is too small, cleaning failure tends to occur, and if it is too large, toner scattering tends to occur.

  On the other hand, the cleaning brush 34 rotates in the direction opposite to the rotation direction of the intermediate transfer belt 16 as indicated by the arrow in FIG. 2, and the linear velocity ratio at the contact portion is set to 1.1. At this time, the linear velocity ratio is preferably set within the range of 0.8 to 1.20.

  Further, the cleaning brush 34 is in contact with the collection roller 35 with a predetermined bite amount (B). The collection roller 35 is made of, for example, a stainless steel cylinder, and rotates in a direction opposite to the rotation direction of the cleaning brush 34, so that residual toner or the like adhering to each brush fiber of the cleaning brush 34 is electrically supplied to the collection roller 35 side. to recover.

  The amount of biting (B) of the cleaning brush 34 with respect to the collection roller 35 is defined as the maximum value at which the tip of the brush fiber of the cleaning brush 34 enters the collection roller 35 when there is no collection roller 35, for example. In the example, β is set to 1.0 ± 0.2 mm. In addition, it is desirable to set in the range of 0.5-1.5 mm as a value of the preferable biting amount (B).

In addition, in the relationship between the bite amount (A) and the bite amount (B),
(A) ≤ (B)
Is preferable,
(A)> (B)
In this case, residual toner tends to accumulate between the brush fibers of the cleaning brush 34.

  The cleaning brush 34 may be fixed or fixed with respect to the intermediate transfer belt 16, but the relative position between the cleaning brush 34 and the intermediate transfer belt 16 is variable in a configuration requiring pressure contact and separation. Become.

  For example, the cleaning brush 34 is supported so as to be swingable via a bearing arm 39 that is rotatable about the rotation axis of the collection roller 35. The bearing arm 39 is rotated via a spring and a cam (not shown) so that the cleaning brush 34 can be pressed against and separated from the intermediate transfer belt 16. The spring is normally biased so as to press the cleaning brush 34 toward the intermediate transfer belt 16, and the cleaning brush 34 is pressed against and separated from the intermediate transfer belt 16 by rotating a cam as necessary. Can be made.

  Further, since the relative positions of both end bearings (not shown) of the cleaning brush 34 are fixed by the bearing arm 39 that can rotate with respect to the rotation shaft of the recovery roller 35, the cleaning brush 34 is always kept in contact with the recovery roller 35. The amount of bite (B) can be bitten.

  Further, the bearing of the collection roller 35 is a conductive bearing on one side, and a bias is applied to the collection roller 35 through this conductive bearing. At this time, the bearing of the cleaning brush 34 is made non-conductive, and the bias applied to the collection roller 35 is not easily lost, so that it can act as a cleaning bias.

  In the present embodiment, the drive roller (not shown) of the collection roller 35 has conductivity, and serves as a cleaning counter electrode. The drive roller is grounded. The cleaning current flows from the recovery roller 35 through the conductive cleaning brush 34 to the driving roller from the intermediate transfer belt 16. By optimizing the resistance of the cleaning brush 34, a necessary and sufficient electric field can be formed between the intermediate transfer belt 16 and the cleaning brush 34, and between the cleaning brush 34 and the collection roller 35.

[Cleaning brush 34]
Hereinafter, a specific configuration of the cleaning brush 34 will be described.

  Thickness of brush fiber: It is desirable that the thickness is 1 to 6 denier.

  Brush fiber material: Nylon such as 6-nylon and 12-nylon, polyester, and acrylic are preferred. Carbon black is added to impart conductivity.

  Brush electrical characteristics: It is preferable to set the brush volume resistance value in the range of 1.0E + 5 to 1.0E + 9Ω. In addition, carbon black is added in order to impart conductivity.

[Recovery roller 35]
Hereinafter, a specific configuration of the collection roller 35 will be described.

  On the surface of the recovery roller 35, a resistance layer 35a having a surface resistivity of 1.0E + 8 to 12Ω / □ mainly composed of a fluororesin is formed.

  The resistance layer 35a mainly composed of this fluororesin can maintain its surface friction coefficient low, and even if the pressing force of the cleaning blade 36 is increased, the driving torque of the recovery roller 35 can be set low. Therefore, it is set so that mechanical jitter hardly occurs.

  Further, the lower the surface friction coefficient of the collection roller 35 is, the less likely the slippage at the blade nip occurs, and the less the surface wear of the collection roller 35 occurs.

  Note that when the friction coefficient is set to 0.2 or less, an increase in torque can be suppressed, and slippage at the blade nip can be further prevented from occurring.

  Further, if the thickness of the resistance layer 35a is too thin, the resistance value varies greatly due to wear, and if the thickness is too thick, the variation in film thickness increases. Further, if the friction coefficient of the collecting roller 35 is large (exceeding 0.2), the cleaning blade may slip through and the wear may be remarkably accelerated (worn at once).

  The conductive agent is preferably a metal oxide based conductive agent rather than carbon conductive, and a filler or the like may be added to improve surface wear resistance and maintain high surface hardness.

  As this filler, potassium titanate whisker or acicular titanium oxide is used, and a conductive filler whose surface is coated with a tin oxide-based conductive agent is preferable.

  Further, the surface roughness Ra of the resistance layer 35a is preferably 1.0 μm or less. This is because if the Ra is larger than 1.0 μm, the cleaning blade 36 is worn out, which causes the slipping of the collection roller 35.

(Evaluation / Measurement)
Using the cleaning brush 34 and the recovery roller 35 configured as described above, continuous printing 100,000 in each of an H / H environment (30 ° C., 80% RH) and an L / L environment (10 ° C., 15% RH). Sheets were implemented and the cleaning properties were evaluated.

  For the evaluation of the cleaning property, the residual toner density of the intermediate transfer belt 16 when a 100% solid image having a width of 2 cm and a length of 28 cm was continuously printed on A4 paper was measured.

  At this time, as a measurement of the residual toner on the intermediate transfer belt 16, the residual toner on the intermediate transfer belt 16 after passing through the cleaning device 21 is peeled off with a transparent tape and pasted on a white paper, and the X-Rite 310TR is measured. The transmission density (TD) was measured using (Transmission density measuring device manufactured by X-Rite).

  In this example, it is evaluated that the transmission density is less than 0.05 and is not possible when it is 0.05 or more.

  In the following evaluation and measurement, Examples 1 and 2 and Comparative Examples 1 and 2 are used. In each example, the conditions of the cleaning brush 34 are the same as shown below, and the environment / recovery roller 35 / intermediate transfer belt 16 are the same. The conditions and evaluation are shown in FIG.

(Cleaning brush 34)
Brush fiber material: 6-nylon (conductive fiber)
Cleaning brush diameter: 14mm
Filament density: 18,600 filaments / cm ²
Filament thickness: An image forming process is executed using 6 denier, and the residual toner density (transmission density) TD in the intermediate transfer belt 16 after passing through the cleaning device 21 is measured.

  As described above, according to the image forming apparatus of the present invention, the collection roller 35 is provided with the resistance layer 35a having a surface resistivity of 1.0E + 8 to 1.0E + 12Ω / □ mainly composed of fluororesin. Low friction and high hardness can be achieved, and a necessary cleaning current can be ensured, so that the cleaning performance can be improved.

  In the above embodiment, the image forming apparatus of the present invention is applied to a rotary four-color full-color printer. However, for example, a six-color printer or a tandem full-color printer may be used. Needless to say, the present invention can be applied to all image forming apparatuses (particularly, full color) such as a copying machine, a printer, a facsimile machine, or a multi-function machine functionally equipped with these.

It is explanatory drawing of an example of the image forming apparatus provided with the cleaning apparatus which concerns on one Embodiment of this invention. FIG. 3 is a cross-sectional view of a main part of a cleaning device in the image forming apparatus according to an embodiment of the present invention. 6 is a chart of a list of evaluation conditions and evaluation results of an example and a comparative example of a cleaning device in an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

1 ... Printer (image forming apparatus)
21 ... Cleaning device 34 ... Cleaning brush 35 ... Recovery roller 35a ... Resistance layer 36 ... Cleaning blade (toner scraping member)

Claims (6)

In an image forming apparatus provided with a cleaning device for removing residual toner after transfer remaining on the surface of an image carrier that transfers a toner image to transfer paper,
A cleaning brush made of conductive fibers that contacts the surface of the image carrier and removes residual toner from the surface of the image carrier, and residual toner removed by the cleaning brush is electrostatically collected from the cleaning brush. The collecting roller, the resistance layer formed on the surface of the collecting roller so as to have a surface resistivity of 1.0E + 8 to 1.0E + 12Ω / □ mainly composed of fluororesin, and the residual toner collected by the collecting roller are scraped off. An image forming apparatus comprising: a toner scraping member.   The image forming apparatus according to claim 1, wherein a friction coefficient of the resistance layer is set to 0.2 or less.   The image forming apparatus according to claim 1, wherein the resistance layer has a thickness of 20 ± 4 μm.   The image forming apparatus according to claim 1, wherein a filler is added to a material component of the resistance layer.   The image forming apparatus according to claim 4, wherein potassium titanate whisker or acicular titanium oxide is used for the filler. The image forming apparatus according to claim 4 , wherein the filler is a conductive filler obtained by coating a surface of potassium titanate whisker or acicular titanium oxide with a tin oxide-based conductive agent.

Images